The Otto cycle engine principle is employed in internal combustion engine operations and which consists of 1) intake/induction stroke, 2) compression stroke, 3) power stroke and 4) exhaust stroke. The efficiency of this type of engine is determined by its compression ratio. The highest compression ratio is limited by the type of fuel (such as unleaded octane rated gasoline alone or with ethanol). Standard octane rated gasoline exhibits a low ignition temperature, this resulting in limited compression during the ignition cycle.
As is known in gasoline engines utilizing the Otto cycle, air is drawn into each cylinder during downward travel of its associated piston. Subsequent upward travel of the piston compresses the air, however the temperature of compression cannot be so high that pre-ignition occurs in the combustion chamber and the fuel air mixture to explode.